Course drafter for marine and aeronautic vessels



Jur ae 19, 1923. 1,458,957

R. H. SCHACHENMEIER COURSE DRAFTER FOR MARINE AND AERONAUTIC VESSELSFiled Au. 20, 1919 2 Sheets-Sheet 1 1 gvwc-mtoz 351 abtomm AM W4W June19, 1923.

R. .H. SCHACHENMEIER C-OURSE DRAFTEH FOR MARlNE AND AERONAUTIG VESSELSFiled Aug. 20, 1919 2 Sheets-Sheet 2 514mm i o z 1106/ 7 31 /M flwww;0m, KW 4' 5 M,

' overcome these draw acks.

Patented June 19, 1923.

UNITED STATES RICHARD HERMANN SGHACHENMEIER, OI KABLSRUHE, GERMANY.

COURSE DRAFTEB. FOR MARINE AND AEBONAUTIC VESSELS.

Application filed August 20, 1919. Serial No. 818,804.

(GIAITED DEB. T113 PROVISIONS OF THE ACT OF IABCK 3, 1921, 41 STAT. Ia,1318 To all whom it may concern:

Be it known that I, RICHARD HERMANN SOHACHENMEIER, a citizen of Germany,residing at and whose post-oilice address is 6 Karlsruhe, Haydnplatz 3,Germany, have invented certain new and useful Improvements in CourseDrafters for Marine and Aeronautic Vessels (for which I have filed anapplication in Germany, December 21, 1915,

Patent No. 349,554, and Germany, June 11,

1918); and I do hereby declare the following to be a full, clear, andexact description of the invention, such'as will enable others skilledin the art to which it appertains, to make and use the same.

Devices are known which draw or record the course traversed by a vehicleor vessel by integrating the equations of motion. But in the deviceshitherto proposed for this purpose a very copious .use of a pliancessimilar to relays and of screws, toot ed racks and the like,is madewhich involve so much performs two tasks simultaneously, viz, thebringing about and maintaining of the vertical position, and theproviding of the forces of inertia to be measured; and in accomplishingthis it avoids the above-mentioned rawbacks of known devices, besidesexcluding all disturbing vibrations and lurchin motions occurring duringthe working 0 the ship in rough seas etc. with theaid of a sw ng ngsystem of adequate dimensions who also permits of the exactitude of themeasurements being carried to any desired degree.

The 0 eration of the devices will be more clearly escribed withreference to the accompanying drawing in which the instrument isdiagrammatically illustrated.

Fig. 1 is a plan view, largely diagrammatic, of my improved coursedrafting apparatus; 70

Fig. 2 is a sectional elevation taken on line 2-2 of Fig. 1;

inertia and friction in the whole apparatus" Fig. 3 is a detail view ofa modification;

that anything like an exact working of the 2 sameis out of the question.Besides, in the known devices a gyroscopic compass or the principle of asimple pendulum is employed for maintaining the vertical position of theapparatus. But if a yroscope is employed on y a few hours will elapsebefore the maintenanceof the vertical osition becomes a very diflicultmatter whi st a simple pendulum is deflected from the vertical positionby centrifugal forces. The object of the resent invention is to This isaccomplished by a device wherein, in order to avoid transmision byintermediate elements and intermediate gear, physical properties ofmatter are employed in which inertia and i friction do not come intoaccount and wherein the maintaining of the vertical position -isaccomplished by means of a pendulum which is set upside down upon apoint and Q the weight or mm of which is supported by a gimbal holderinsuch manner that when changes of direction and speed occur the forces ofinertia of the pendulum are taken.

up by the points of support whilst maintaining its vertical position.The device thus Fig. 4 is a sectional view taken on line 44 of Fig. 1;

Fi 5 is a detail view of a modification, and ig. 6 is a viewillustrating a modified form of recording apparatus.

Ifm, 3 are co-ordinates extending at right angles to each other on aplane in which the motion takes place and, for example, coinciding withthe north-south and east-west directions, and if X, Y represent thecomponents of active force corresponding to the said coordinates, thecurve of travelds determined, if the initial position and speed areknown, by the equations of motion:

dx dy dt dt".

wherein t denotes time and M the mass of the moved body. Thecourse-drafter must therefore perform the following functions:

(A) take up the forces X, Y which act upon a mass M during the course ofthe motion, and

(B) integrate the equations (1).

The present invention relates primaril to a device for carrying out thefunction A) which constantly indicates the vertical di- 1 0 the motion.This device consists of a pendu-- lum w, b, c (Fig. 2, the pendulumbodies a, 5 having a total mass M) stood on a point and combined with agimbal f in such manner that the force of gravity acting on the mass ofthe pendulum a, Z) suppresses displacements of the gimbal from thevertical position in consequence of its comparatively large size and ofthe large levers that come into play whilst the forces of inertia X, Yof the mass a 6 are taken up by springs or, by cylinders c, c containingliquid so as to avoid fluctuations of the gimbal. To this end the planeof the four piston rods d, d, which, for the purpose of avoiding a rigidconnection, may be replaced by springs p, p, as shewn in Fig. 3,coincides with the plane .of the two gimbal pivots f f in the positionof rest, and the center of gravity of the masses a, Z of the pendulumlies within or slightly below the plane. The pressures X, Y of theliquids are transferred to points of utilization by any convenientmeans, here shown as hydraulic conduits q communicating with thecylinders e and receiving pressure therefrom.

In Figs an instrument is shewn which measures the forces taken up by thepistons '0, o. In this instance the swinging? system consists byway ofexample of a horizontal annular disk r which is revoluhle about acentral vertical and which is he t in a position out equilibrium by aspring 5. The hydraulic pressure X transmitted b means of the conduitsg, g from the cylin ers c, e to a second setoi cylinders 42 wh cooperate with the annular disk as "Within the cylinders e provided erigidly interconnected by means of a rod 16 having a portion of lengthtoothed at 11 the manner of a rack to mesh with a pinion 12 which isprovided on the shaft 515 which supports the disk 2''. This mechanismserves to imgart motion to the shaft 15.

peration of the apparatus will be clear from the above description. Whenthe course of the vehicle is the pendulum will tend to tip out of thevertical position and consequently the liquid in one or more of thecylinders e is subjected to pressure, which pressure is transmitted thi'h. lay draulic conduits g to the corresponding cylinders e and reactsagainst pistons Since the rods connecting the pistons o working in thecylinders c are rigid will be a tendency toward diminution of pressurein the remaining cylinders e and consequently in the correspondingcylinders 6. These unbalanced forces acting on pistons u give them alongitudinal motion and, through the rack 11 and pinions 12, turn thedisl: r about its axis an amount proportional to the magnitude of theimpulse'conveyed to the pieton e, that is, proportional to the force'iuthe direction of the w coordinate which is developed at the pendulum dueto the change in the course. A second pair of conduits and a second diskarrangement 7- is provided to record the force impulses in the ydirection, the arrangement being identical with that just described.

The annular disk with its spring forms a mechanical system which iscapable of executing its own free motions and whose period ofoscillation depends on the power of the s ring and on the moment ofinertia of the disk. The latter may be increased to any desired extentwithout increasin the weight of the disk by selecting a suitable radiusof the same. In this manner the period of oscillation is made of suchlength that it is large compared to the intervals within whichdisturbing impulses are imparted to the pendulum a, b, c by themacbinery wind, lurching of the vessel in seas or the like. Theseimpulses will then cause no appreciable deflection of the annular disk.The period of oscillation. is also arranged to be short compared to thetimes in which changes of motion of thevessel (i. e., changes of speedor direction) take place. If any direction which approximately coincideswith the main line of travel is taken as the axis of abscissas, thecourse may be taken to represent a periodic or nonperiodic curve whoseamplitudes are indicated with greater exactitude and with the lesser lagthe smaller the natural periodic time of the annular disk is.

If, for example, it amounts to 1} of the time in which the smallestsinusoidal arcs of the track are traversed, this will sufiice to makeerrors in the readings of the apparatus practically negligible.

A. regulatable damping device, shown diagrammatically at 13- and whichmay be of any well known type adapted for use with a disk oscillating ona vertical axis, is provided on the supporting shaft 15 of the disk 7'and is preferably adjusted to render the oscillations of the disk rmoderately damped in character. I have found that damping of such anature as to permit the disk 9. complete oscillation to and frosubsequent to a single impulse is the most desirable in practies.

The spring i serves to limit the extent of rotation of the disk 7 and isadjusted according to the mass of the pendulum. A pendu-' lum of largemass has a correspondingly large inertia and will exert a large turning,force on the disk 1". The restraining spring 2" is consequently adjustedfor a given pendulum to a tension commensurate with the turning movementwhich it will be called upon to restrain.

The'communication of the angle a ascertained by the above-describeddevice to an integrating device is accomplished by means of a flatmirror is which is attached to the annular disk 1' and whose planecoincides with the prolongation of the axis of rotation. A pencil ofrays 11- emanating from a fixed source of light is reflected by themirror to a set of soot-covered thermo-electric cells m which belong tothe integration device. As the reflected rays turn through an anglewhich is twice as large as that of the mirror the accuracy of thereadings will be thereby increased.

An additional device corrects the values determined by the thermalcells, makin them appear as though the piston rods (I always coincidedwith the principal points of the compass, as not bem technically ossibleto actually keep the to s themselves in this position. To accomplishthis the whole apparatus is rou hly adjusted b mean of a relayelectrical y associated wit a com ass so as to coincide approximatelywith t e principal points of the compass.

A more accurate correction is obtained by the means of a mirror amounted in parallelism with the axis of the pendulum and stationaryrelative to the piston rods d. On

the outer edge of the compass disk k and" stationary relative to thisdisk and to the rods (1 is a light source 9 adapted to direct a beam 21upon the mirror 8', from whence it is reflected upon an electricalconductor h whose resistance varies with the ntensity of light to whichit is subjected, 1t being understood that the light source will besuitably shaded if desired so that the ray of light incident u on theconductor h will consist substantial y of a single beam as in dicated inthe drawings. Such resistance may be a sooted wire, a platinum strip, orany well known conductor of this type. The arrangement of the conductorit re ative to the light source 20 and mirror a is made such that itschange of resistance is proportional to the cosine of the an le ofdeyiation of the piston rods d from t is principal oints of the com ass,and thus any current sowing through the conductor is in effectmultiplied by the cosine of this angle of deviation.

The small glowlam ma be substituted by a radium preparation Fig. 5,located at the same spot and whose rays impinge upon a so-calledionization-chamber which takes the place of the metallic reslstan'ce.Instead of the mirror 8 an.absorb1ng screen t which is fixed to thependulum and has a cross-section of suitable shape is placed 1n the pathof the rays, so that they penetrate diflerent thicknesses/of theabsorbing material (aluminium e. g.) according to the position of thecompass card and thus give rise to changes of the ionization, which inturn alters the electric conductivity of the gaseous path in J.

The forces X, Y which are to be integrated may be utilized toproduceelectric currents whose intensities are proportional to theforces. This is accomplished by means of the thermoelectric cells mpreviousl referred to in the description. of the" osci latlng disk r;The light rays reflected from mirror 8 impinge on cells m which are sosituated as to receive varyingamjounts'of light as the angle ofoscillatwnbfdiskr grating the X and Y components of force with respectto time. The cells m and con-" ductor b. are connected in series, thevariatlon in current due to the varying resistance of conductor It beingin effect superimposed uponthe current derived from cells m andeffecting a correction for the deviation of piston rods d from therincipal points of the compass. In Fig. 4 t are is shown a single disk rand a single set of thermo-electric cells. These integrate, for example,the forces acting in the a: direction, and it is to be understood thatan identical system may be provided for the integration of the forcesacting in the 3 direction.

The integration of the electric currents from these two systems ofconnections may be accomplished in various manners. For example, anintegrating meter 23 may be placed in circuit with cells m and providedwith a. pinion 24 cooperating with a rack 25 which carries a contact 26adapted to slide along a resistance 27 through which a current 15flowing from the source 28, and thereby regulate the amount ofresistance in the circuit. A second meter 29 is placed in circuit withthe source 28.- This meter will be actuated proportionally to thecurrent flowing through resistance 27. For recordi purposes the secondmeter is provided wit a gear mechanism 30 bearing a stylus u which isrigidly attached to the gear and consequently has a motion proportionalto the ai-coordinate.

A second set of integrating devices is provided for the integration ofthe y component of current in a manner identical with that described forthe a: component. The.

integrating mechanism for the 3,! component' of current is, however,connected to a drum 32 carryinga chart upon which the stylus u isadapted to move. The movement of the drum is proportional to the 3coordinate of displacement and that of the stylus to the a: coordinate.Hence the curve traced on the chart bears a definite relation to thecourseot' the vehicle and may be used as a chart for indicating thecourse.

All of the above-mentioned parts of the. course-(hatter are suspended,individually or several together, on springs so that fluctuations andknocks are eliminated both in the horizontal and the vertical direction.The strength of the springs and of the damping contrivances which mightbe required depends on the nature of the disturbing impulses whichdiffer with the kind of the vessel or vehicle in question.

Other devices which are sensitive to light may be employed instead ofthose already mentioned, for example selenium cells, alkali cells orother devices affected b light.

A very simple apparatus will be t'ained if it is only required to recordthe forces X, Y as functions of time and the curves thus produced areintegrated graphically or by means of tables. This integration is easilycarried out, because the curves are very simple, consisting mostly ofstraight pieces.

Instead of the cylinders e, e containing a liquid, crystals of quartz,turmalin, or other material having similar electrical properties may beused. This embodiment of my invention is illustrated in Fig. 6, whereinquartz crystals 31 are spaced around the inner giinbal ring and aresubjected to compressive forces when the course of the vehicle is chaned due to the inertia of the pendulum, in t e same manner asthehydraulic cylinders of Fig. 1 are Sub ected to pressure. According tothe well known roperty of such crystals an electromot ve orce isgenerated under the influence of the physical forces acting on thecrystals, and the magnitude of these electric potentials may be recordedby connecting the crystals in circuit with a sensitive galvanometer 32.as shown. The deflections of the galvanometer are recorded by means of amirror 33 rotatable with the moving element of the galvanometer and uponwhich is incident a beam of light 34 from a 'suitable source. The beam34 after reflection from the mirfilm and serves to trace an impressionon the film bearing a definite relation to the electromotive forcesgenerated by the uartz crystals. It is, of course, understood t at onlya single pencil of rays 34 will be permitted to impinge on the mirror,simlar galvanometer ,is 1provided in circuit wit "he pair of crysta s31' which are displaced 90 about the periphery of the gimbal ring andserve to record the forces act ing at right angles to those recorded bythe crystals 31. In this manner a photographic record of the coursepursued by the vehicle is recorded, the team of light serving to trace acurve on the sensitized film similar to the curve traced by the stylusarrange ment previously described.

The mass a, Z) of the pendulum together with the spring p, p representsan oscillating system that vibrates in a horizontal plane and whosenatural period of vibration and damping are determined on the sameprinciples as those of the annular disk. On these same principles thenatural periodic times of the galvanometers and the damping ef fectsrequired for the same are determined. The corrections required withregard to the chief points of the compass may be carried out preciselyas explained above.

Instead of sending the currents to be integrated through galvanometersthey may be sent directly through ampere-hour meters whose magnetic ormechanical inertia is such that suitable average values are integrated.

It is to be understood that the various details and arrangement of theparts of the apparatus may be varied within the full sco e of theappended claims. It is further to understood that the various details,such as the particular means of integrating the electric currents, theparticular type of current sources and contact arrangements employed,the general arrangement of the circuits connecting the principalapparatus with the indicating devices, and the like, do not constitutean essential part of the invention and are not incorporated in theclaims.

I claim 1. A course-drafter for recording the track traversed by avessel by integration of the equations of motion comprising, a gimbal, apendulum reversed so that its weight is at the top and its bar pointsdownwards, whereby the weight of the pendulum 0 poses deflections of thevertical axis of tlie gimbal from its normal position, a carrying memberattached to the gimbal and supporting the bottom point of the pendulumbar. and members between the weight of the pendulum and the gimbal fortaking up the forces exerted due to the mass of the pendulum whilstmaintaining its vertical position when the direction or speed of thevessel changes.

2. A course-drafter for recording the track traversed by a vessel byintegration of the equations of motion comprising, a gimbal, a pendulumsuspended in the said gimbal with its weight at the to and its barpointing downwards, the weig t of the pendulum opposing deflections ofthe vertical axis of the gimbal from its normal position, and membersbetween the weight of the pendulum and the gimbal for taking up theforces exerted due to the mass of the pendulum whilst maintaining itsvertical position when the direction or speed of the vessel changes.

8. A course-drafter for recording. the track traversed by a vessel byintegration of tical axis 0 the equations of motion comprising, agimbal, a pendulum suspended in the said gimbal with its weight at thetop and its bar pointing downwards, the weight of the pendulum opposingdeflections of the vertical axis of the gimbal from its normal position,members between the wei ht of the pendulum and the gimbal for tafiing upthe forces exerted due to the mass of the pendulum whilst maintainingits vertical position when the direction or speed of the vessel changes,an oscillating recording member for recording the changes in the pathtraversed by the vessel, and means for transferring the said forces tothe oscillating recording member.

4. A course-drafter for recording the track traversed by a-vessel byintegration of the equations of motion comprising, a gimbal,'a pendulumsuspended in the said 'mbal with its weight at the top and its atointing downwards, the wei ht of the pen ulum opposing-deflections o theverthe gimbal from its normal position, members between the weight ofthe pendulum and the gimbal for taking up the forces exerted due to themass of the pendulum whilst maintaining its vertical position when thedirection or speed of the vessel changes, an oscillating recordingmember for recording the changes in the path traversed by the vessel,means for transferring the said forces to the oscillating recordingmember, and correcting means for making the readings of the devicecorrespond to a system of co-ordinates in space such as the principalpoints of the compass, this correcting means comprising a radiatingdevice sending out rays from a certain direction, a changeableresistance affected by the said rays and affecting the recording member,and a ray-afi'ecting device fixed to the said pendulum.

5. A course-drafter for recording the track traversed by a vessel byintegration of the equations of motion comprising, a gimbal, a pendulumsuspended in the said imbal with its weight at the top and its atointing downwards, the wei ht of the pendiilum opposing deflections othe vertical axis of the gimbal from its normal position, membersbetween the weight of the endulum and the gimbal for taking up tlieforces exerted due to the mass of the pendulum whilst maintaining itsvertical position when the direction or speed of thevessel changes, anoscillating member with a vertical axis, a radiating member sending outrays from a fixed point, a ray-affecting member fixed en the saidvertical axis, means for transferring the forces to the said oscillatingmember, and an integrating device controlled by the rays sent out by theradiating member and affected by the ray-affecting member.

6. A course-drafter for recording the track traversed by a vessel byintegration ofthe equations of motion comprising, a gimbal, a pendulumsuspended in the said gimbal with its Weight at the top andv its barointing downwards, the weight of the pen ulum opposing deflections ofthe vertical axis of the gimbal from its normal po sition, membersbetween the wei ht of the pendulum and the gimbal for taking up theforces exerted due to the mass of the pendulum whilst maintaining itsvertical posi tion when the direction or speed of the vessel changes, anoscillating member with a vertical axis, a radiating member sending outrays from a fixed point, a ray-affecting member fixed on the saidvertical axis, means for transferring the forces to the said oscillatingmember, a controlling device sensitive to the said rays sent out by theradiating member and affected by the rayafi'ecting member, and anintegrating device controlled by the controlling device.

7. A course-drafter for recording the track traversed by a vessel byintegration of the equations of motion comprising, a gimbal, a pendulumsuspended in the said gimbal with its weight at the to and its barpointing downwards, the wei t of the pendulum opposing deflections 0 thevertical axis of the gimbal from its normal position, members betweenthe weight of the pendulum and the gimbal for taking up the forcesexerted due to the mass of the pendulum whilst maintaining its verticalposition when the direction or speed of the vessel changes, anoscillating member with a vertical axis, a radiating member sending outrays from a fixed point, a ray-affecting member fixed on the saidvertical, axis, means for transferring the forces to the saidoscillating member, a battery of thermoelectric cells sensitive to thesaid rays sent out by the radiating member and affected by theray-afiectin member, and an integratlng device control ed by the batteryof thermoelectric cells.

8. A course-drafter for recording the track traversed by a vessel byintegration of the equations of motion comprising, a gimbal, a pendulumsuspended in the said gimbal with its weight at the to and its barointing downwards, the weig t of the pen ulum opposing deflections ofthe vertical axis of the gimbal from its normal position, membersbetween the weight of the pendulum and the gimbal for takin up theforces exerted due to the mass 0 the pendulum whilst maintaining itsvertical position when the direction or speed of the vessel changes, anoscillating memher with a vertical axis, a radiating member sending outrays from a fixed point, a rayafi'ecting member fixed on the saidvertical axis, means for transferring the forces to the said oscillatingmember, a controlling device ,sensitive to the said rays sent out Intestimony whereof I aflix my signm by the radiating member and affectedb ture, in presence of two witnesses.

the ray'ifiecting member the comm m. RICHARD nmmm scmcunmmk. ling devicetransformin the varying forces v 5 into electric currents 0 proportionalvary- Witnesses:

ing intensities, and an integrating device M. KI'JHN. controlled by thecontrolling device. E. REHM..

